[llvm] [RISCV] Add copyPhysRegVector to extract common vector code out of copyPhysRegVector. (PR #70497)

Craig Topper via llvm-commits llvm-commits at lists.llvm.org
Fri Oct 27 12:14:40 PDT 2023


================
@@ -350,176 +438,118 @@ void RISCVInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
                                         &RISCV::FPR32RegClass);
       Opc = RISCV::FSGNJ_S;
     }
-    IsScalableVector = false;
-  } else if (RISCV::FPR32RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::FSGNJ_S;
-    IsScalableVector = false;
-  } else if (RISCV::FPR64RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::FSGNJ_D;
-    IsScalableVector = false;
-  } else if (RISCV::VRRegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV1R_V;
-    LMul = RISCVII::LMUL_1;
-  } else if (RISCV::VRM2RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV2R_V;
-    LMul = RISCVII::LMUL_2;
-  } else if (RISCV::VRM4RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV4R_V;
-    LMul = RISCVII::LMUL_4;
-  } else if (RISCV::VRM8RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV8R_V;
-    LMul = RISCVII::LMUL_8;
-  } else if (RISCV::VRN2M1RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV1R_V;
-    SubRegIdx = RISCV::sub_vrm1_0;
-    NF = 2;
-    LMul = RISCVII::LMUL_1;
-  } else if (RISCV::VRN2M2RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV2R_V;
-    SubRegIdx = RISCV::sub_vrm2_0;
-    NF = 2;
-    LMul = RISCVII::LMUL_2;
-  } else if (RISCV::VRN2M4RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV4R_V;
-    SubRegIdx = RISCV::sub_vrm4_0;
-    NF = 2;
-    LMul = RISCVII::LMUL_4;
-  } else if (RISCV::VRN3M1RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV1R_V;
-    SubRegIdx = RISCV::sub_vrm1_0;
-    NF = 3;
-    LMul = RISCVII::LMUL_1;
-  } else if (RISCV::VRN3M2RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV2R_V;
-    SubRegIdx = RISCV::sub_vrm2_0;
-    NF = 3;
-    LMul = RISCVII::LMUL_2;
-  } else if (RISCV::VRN4M1RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV1R_V;
-    SubRegIdx = RISCV::sub_vrm1_0;
-    NF = 4;
-    LMul = RISCVII::LMUL_1;
-  } else if (RISCV::VRN4M2RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV2R_V;
-    SubRegIdx = RISCV::sub_vrm2_0;
-    NF = 4;
-    LMul = RISCVII::LMUL_2;
-  } else if (RISCV::VRN5M1RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV1R_V;
-    SubRegIdx = RISCV::sub_vrm1_0;
-    NF = 5;
-    LMul = RISCVII::LMUL_1;
-  } else if (RISCV::VRN6M1RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV1R_V;
-    SubRegIdx = RISCV::sub_vrm1_0;
-    NF = 6;
-    LMul = RISCVII::LMUL_1;
-  } else if (RISCV::VRN7M1RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV1R_V;
-    SubRegIdx = RISCV::sub_vrm1_0;
-    NF = 7;
-    LMul = RISCVII::LMUL_1;
-  } else if (RISCV::VRN8M1RegClass.contains(DstReg, SrcReg)) {
-    Opc = RISCV::VMV1R_V;
-    SubRegIdx = RISCV::sub_vrm1_0;
-    NF = 8;
-    LMul = RISCVII::LMUL_1;
-  } else {
-    llvm_unreachable("Impossible reg-to-reg copy");
+    BuildMI(MBB, MBBI, DL, get(Opc), DstReg)
+        .addReg(SrcReg, getKillRegState(KillSrc))
+        .addReg(SrcReg, getKillRegState(KillSrc));
+    return;
   }
 
-  if (IsScalableVector) {
-    bool UseVMV_V_V = false;
-    bool UseVMV_V_I = false;
-    MachineBasicBlock::const_iterator DefMBBI;
-    if (isConvertibleToVMV_V_V(STI, MBB, MBBI, DefMBBI, LMul)) {
-      UseVMV_V_V = true;
-      // We only need to handle LMUL = 1/2/4/8 here because we only define
-      // vector register classes for LMUL = 1/2/4/8.
-      unsigned VIOpc;
-      switch (LMul) {
-      default:
-        llvm_unreachable("Impossible LMUL for vector register copy.");
-      case RISCVII::LMUL_1:
-        Opc = RISCV::PseudoVMV_V_V_M1;
-        VIOpc = RISCV::PseudoVMV_V_I_M1;
-        break;
-      case RISCVII::LMUL_2:
-        Opc = RISCV::PseudoVMV_V_V_M2;
-        VIOpc = RISCV::PseudoVMV_V_I_M2;
-        break;
-      case RISCVII::LMUL_4:
-        Opc = RISCV::PseudoVMV_V_V_M4;
-        VIOpc = RISCV::PseudoVMV_V_I_M4;
-        break;
-      case RISCVII::LMUL_8:
-        Opc = RISCV::PseudoVMV_V_V_M8;
-        VIOpc = RISCV::PseudoVMV_V_I_M8;
-        break;
-      }
-
-      if (DefMBBI->getOpcode() == VIOpc) {
-        UseVMV_V_I = true;
-        Opc = VIOpc;
-      }
-    }
-
-    if (NF == 1) {
-      auto MIB = BuildMI(MBB, MBBI, DL, get(Opc), DstReg);
-      if (UseVMV_V_V)
-        MIB.addReg(DstReg, RegState::Undef);
-      if (UseVMV_V_I)
-        MIB = MIB.add(DefMBBI->getOperand(2));
-      else
-        MIB = MIB.addReg(SrcReg, getKillRegState(KillSrc));
-      if (UseVMV_V_V) {
-        const MCInstrDesc &Desc = DefMBBI->getDesc();
-        MIB.add(DefMBBI->getOperand(RISCVII::getVLOpNum(Desc))); // AVL
-        MIB.add(DefMBBI->getOperand(RISCVII::getSEWOpNum(Desc))); // SEW
-        MIB.addImm(0); // tu, mu
-        MIB.addReg(RISCV::VL, RegState::Implicit);
-        MIB.addReg(RISCV::VTYPE, RegState::Implicit);
-      }
-    } else {
-      int I = 0, End = NF, Incr = 1;
-      unsigned SrcEncoding = TRI->getEncodingValue(SrcReg);
-      unsigned DstEncoding = TRI->getEncodingValue(DstReg);
-      unsigned LMulVal;
-      bool Fractional;
-      std::tie(LMulVal, Fractional) = RISCVVType::decodeVLMUL(LMul);
-      assert(!Fractional && "It is impossible be fractional lmul here.");
-      if (forwardCopyWillClobberTuple(DstEncoding, SrcEncoding, NF * LMulVal)) {
-        I = NF - 1;
-        End = -1;
-        Incr = -1;
-      }
+  if (RISCV::FPR32RegClass.contains(DstReg, SrcReg)) {
+    BuildMI(MBB, MBBI, DL, get(RISCV::FSGNJ_S), DstReg)
+        .addReg(SrcReg, getKillRegState(KillSrc))
+        .addReg(SrcReg, getKillRegState(KillSrc));
+    return;
+  }
 
-      for (; I != End; I += Incr) {
-        auto MIB = BuildMI(MBB, MBBI, DL, get(Opc),
-                           TRI->getSubReg(DstReg, SubRegIdx + I));
-        if (UseVMV_V_V)
-          MIB.addReg(TRI->getSubReg(DstReg, SubRegIdx + I),
-                     RegState::Undef);
-        if (UseVMV_V_I)
-          MIB = MIB.add(DefMBBI->getOperand(2));
-        else
-          MIB = MIB.addReg(TRI->getSubReg(SrcReg, SubRegIdx + I),
-                           getKillRegState(KillSrc));
-        if (UseVMV_V_V) {
-          const MCInstrDesc &Desc = DefMBBI->getDesc();
-          MIB.add(DefMBBI->getOperand(RISCVII::getVLOpNum(Desc))); // AVL
-          MIB.add(DefMBBI->getOperand(RISCVII::getSEWOpNum(Desc))); // SEW
-          MIB.addImm(0);  // tu, mu
-          MIB.addReg(RISCV::VL, RegState::Implicit);
-          MIB.addReg(RISCV::VTYPE, RegState::Implicit);
-        }
-      }
-    }
-  } else {
-    BuildMI(MBB, MBBI, DL, get(Opc), DstReg)
+  if (RISCV::FPR64RegClass.contains(DstReg, SrcReg)) {
+    BuildMI(MBB, MBBI, DL, get(RISCV::FSGNJ_D), DstReg)
         .addReg(SrcReg, getKillRegState(KillSrc))
         .addReg(SrcReg, getKillRegState(KillSrc));
+    return;
+  }
+
+  // VR->VR copies.
+  if (RISCV::VRRegClass.contains(DstReg, SrcReg)) {
+    copyPhysRegVector(MBB, MBBI, DL, DstReg, SrcReg, KillSrc, RISCV::VMV1R_V,
+                      /*NF=*/1, RISCVII::LMUL_1, RISCV::sub_vrm1_0);
+    return;
+  }
+
+  if (RISCV::VRM2RegClass.contains(DstReg, SrcReg)) {
+    copyPhysRegVector(MBB, MBBI, DL, DstReg, SrcReg, KillSrc, RISCV::VMV2R_V,
+                      /*NF=*/1, RISCVII::LMUL_2, RISCV::sub_vrm1_0);
----------------
topperc wrote:

Note the SubRegIdx parameter is only used when NF != 1, so its value doesn't matter. The original code used sub_vrm1_0 for NF==1. There is no sub_vrm8_0 so we can't make it match the LMUL for NF=1.

https://github.com/llvm/llvm-project/pull/70497


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